Quantifying and comparing light environments are crucial for interior lighting, architecture and visual ergonomics. Yet, current methods only catch a small subset of the parameters that constitute a light environment, and rarely account for the light that reaches the eye. Here, we describe a new method, the environmental light field (ELF) method, which quantifies all essential features that characterize a light environment, including important aspects that have previously been overlooked. The ELF method uses a calibrated digital image sensor with wide-angle optics to record the radiances that would reach the eyes of people in the environment. As a function of elevation angle, it quantifies the absolute photon flux, its spectral composition in red–green–blue resolution as well as its variation (contrast-span). Together these values provide a complete description of the factors that characterize a light environment. The ELF method thus offers a powerful and convenient tool for the assessment and comparison of light environments. We also present a graphic standard for easy comparison of light environments, and show that different natural and artificial environments have characteristic distributions of light.

量化和比较照明环境对于室内照明，建筑和视觉人体工程学至关重要。然而，当前的方法仅捕获构成光环境的参数的一小部分，并且很少考虑到达眼睛的光。在这里，我们描述了一种新的方法，即环境光场（ELF）方法，该方法量化了表征光照环境的所有基本特征，包括以前被忽略的重要方面。ELF方法使用带有广角光学元件的经过校准的数字图像传感器来记录会到达环境中人眼的辐射。作为仰角的函数，它可以量化绝对光子通量，其红，绿，蓝分辨率的光谱组成以及其变化（对比度跨度）。这些值共同提供了表征光照环境的因素的完整描述。因此，ELF方法为评估和比较光照环境提供了一个强大而便捷的工具。我们还提出了一种图形标准，可轻松比较光照环境，并显示出不同的自然和人造环境具有特征性的光照分布。